Immunocytochemistry, FISH

Yes. A thin slice of tissue can be fixed to a microscope slide and incubated with a specific labelled probe molecule that hybridizes only to the transcript or protein of interest. The probe can be complementary DNA or antisense RNA when RNA is the target, this is called in situ hybridization (ISH). Proteins in a tissue slice can be expressed as recombinant tagged fusion proteins or detected by antibodies the latter is called in situ immunocytochemistry. The label can be radioactive, such as or commonly the more precise H, fluorescent (FISH), or an enzyme that produces a colored product. The signal is then recorded by light microscopy to permit localization of the transcript or protein. 

Margolis-Kazan, H., and Schreibman, M. P., 1981, Cross-reactivity between human and fish pituitary hormones as demonstrated by immunocytochemistry, Cell Tis. Res., 221 257. 

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